The present invention relates to a method and apparatus for electrodepositing on a substrate. In particular, the present invention relates to a method and apparatus for electrodeposition (eg, electroplating), electroetching, and/or electropolishing in semiconductor device manufacturing.
In the production of microelectronic devices, metal may be plated on a semiconductor for a variety of purposes. The metal may be deposited to form vias or conductive lines, such as wiring structures. Typically, metal is plated on the substrates in cells that hold a reservoir of a plating solution that includes at least one metal and/or alloy to be plated on the substrate.
Plating baths are commonly used in microelectronic device manufacture to plate at least one material, such as a metal on a substrate for a wide variety of applications. For example, plating baths may be utilized for electroplating and/or electroless plating on substrates of one or more metals and/or alloys.
The present inventors believe that contact arrangements used in a typical electroplating apparatus cause slight imperfections on the copper (Cu) seed layer during plating. These known contact arrangements have contact points located, for example, at the ends of 128 short xe2x80x9carms.xe2x80x9d These arms take up compression when, eg, sealing the wafer in a xe2x80x9cclamshellxe2x80x9d for electroplating. See, for example, known electroplating tools such as the SABRE Electro-fill System marketed by Novellus Systems, Inc, San Jose, Calif. See, also, U.S. Pat. No. 6,074,544 (Method Of Electroplating Semiconductor Wafer Using Variable Currents And Mass Transfer To Obtain Uniform Plated Layer) and U.S. Pat. No. 6,139,712 (Method Of Depositing Metal Layer), which are both incorporated in their entireties herein by reference. When a Cu seed layer is greater than 1000 A thickness, these contacts don""t pose a serious problem. However, as the industry moves to thinner and thinner seed layers, these contacts do enough damage to cause large variations in plated film thickness. Having the actual contact point located at the end of a xe2x80x9cmoment armxe2x80x9d induces a certain, be it slight, amount of motion in the xe2x80x9cxxe2x80x9d direction in order to accommodate for the xe2x80x9czxe2x80x9d motion required for sealing the wafer in the clamshell for electroplating. When the movement in the xe2x80x9cxxe2x80x9d direction occurs, it scratches across the seed layer reducing the number of good electrical connections.
The present invention provides an apparatus for depositing material, electroetching, and/or electropolishing on a surface of a substrate. The apparatus includes at least one electrical contact for contacting the substrate and providing an electrical connection to the substrate. The at least one contact is movable only in a vertical direction with respect to the substrate. A voltage source is connected to the at least one contact.
The present invention also includes a method for depositing material on a surface of a substrate. The method includes only vertically (eg, in a z direction) engaging a substrate on which a material is to be deposited with at least one electrical contact for vertically contacting the substrate and providing electrical connection to the substrate, without causing any lateral motion (eg, in an x or a y direction). A voltage source is connected to the at least one electrical contact.
Still other objects and advantages of the present invention will become readily apparent by those skilled in the art from the following detailed description, wherein it is shown and described only the preferred embodiments of the invention, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive.